Shoe centerless grinding is a widely used process for the finishing of precision cylindrical components. However, there are two problems in shoe centerless grinding which are (1) waviness due to lobing and chatter, (2) thermal-damage resulting from overheat at the contact area between the rear-shoe and workpiece. Current shoe centerless grinding machine applied in industry can not resolve these problems due to the following reasons:
(1) The geometric setup is manually operated and not accurate. The workpiece quality depends on the operator's experience. PA1 (2) Pivot-structure of the shoes causes support stiffness reduction and introduces more waviness. PA1 (3) Stiff rear-shoe structure results in full geometric error feedback to the cutting point and heat accumulation in the contact area between the workpiece and the rear shoe. PA1 (4) The process parameter configuration is not effective in suppressing lobing and chatter.
Industrial and academic researchers have made much contribution to resolving these problems. Currently, two lobing control methods are geometric setup selection in which the (.alpha.-.beta.) cloud diagram is a very popular tool, and speed control in which the wheel speed variation or work speed adjustment is used to suppress lobing. However, there is no approach so far that can provide a lobing-free operation.
For thermal-damage problem, there has been little attention from the academia. Some methods used in industry to lower the temperature include cooling, reducing the contact area between the shoe and workpiece or reducing the grinding force. Unfortunately a decrease in contact area will cause a lobing problem and a smaller grinding force decreases the productivity.
There has been no effective solution to the lobing and thermal problems in shoe centerless grinding. A device which can overcome both problems is needed to obtain high quality circular components.